Golf club head

ABSTRACT

This invention provides a golf club head that is made with simple structure and can be changed of its total shape and mounting position of a golf club shaft by partly replacing its parts. Therefore it is superior in flexibility of choosing its shape, and in versatility. Since the golf club head can commonize many parts, inventory control will be easy, and is superior in mass productivity. Further, beginner and amateur players can easily customize the center of gravity position depending on their preference. Therefore, they can use the golf club head for a long term. Further, it is superior in maintenance characteristics, the handling characteristics, and the resource saving characteristics. It contributes to not only the golf population but also, resources-saving and environmental protection.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is related to the Japanese Patent ApplicationNo. 2010-125214, filed May 31, 2010, the entire disclosure of which isexpressly incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a golf club head which is capable ofcustomizing its center of gravity position and mounting position of aclub shaft depending on user preference, thus providing superior inversatility and easiness in maintenance.

2. Description of Related Art

The principal object of developing conventional golf club was increasinga distance of a golf ball. Therefore most of the designs such asmaterials or loft angle of the head were in the mainstream. Andcustomization or adjustment depending on individual user preference,their tendency, or physical condition, such as their age, was notresearched or examined so far.

Therefore the applicant filed a patent application (Japan Utility ModelPatent No. 3148909) in Japan.

The gazette of the Utility Model Patent No. 3148909, hereinafter called“the gazette”, discloses “a golf club head comprising a pair of balanceadjustment portions which are provided in a side-to-side arrangement andeach of which accommodates one or a plurality of balancers so that thebalancers are detachable, the balance adjustment portions includingcovers which detachably cover a toe side and a heel side of a back facesurface side of a head body respectively, the covers including balanceraccommodation recesses which surround outer peripheries of the balancersrespectively, and a pair of gravity center height adjustment portionswhich are formed in each cover in an up-and-down arrangement so as to belocated at a crown side and a sole side of the head body respectivelyand so as to be separated from the balancer accommodation recessesrespectively, each gravity center height adjustment portionaccommodating one or a plurality of gravity center height adjustmentbalancers therein.”

The golf club head disclosed in the gazette was capable of beingadjusted in its center of gravity not only a front-and-back directionand a left-and-right direction, but also in top-and-bottom directiondepending on user personality. Thus it was easy to control golf balls bygiving back-spin or top-spin to golf balls. And it was superior inversatility or handling. It was capable of adjusting its center ofgravity in a wide range, and superior to flexibility of the center ofgravity adjustment.

However, the adjustment includes selecting the balancers, adjusting theheight of the center of gravity, selecting materials and mass of thebalancer. Thus, the adjustment of the center of gravity by selectingcombination of the number and allocation of the balancers requirescomplicated work and a lot of work hours to finally decide the mostsuitable position.

Such a fine adjustment was necessary in the case of the advanced playersthe professional player. However, in the case of beginners and amateurs,such fine adjustment was unnecessary. Thus the development of the golfclub head which could offer generous balance adjustment very easily wasrequested.

BRIEF SUMMARY OF THE INVENTION

This invention provides a golf club head which could offer generousbalance adjustment. The golf club head can be changed of its total shapeand mounting position of a golf club shaft by partly replacing itsparts. Therefore it is superior in flexibility of choosing its shape,and in versatility. Since the golf club head can commonize many parts,inventory control will be easy, and is superior in mass productivity.Beginner and amateur players can easily customize the center of gravityposition depending on their preference. Therefore, they can use the golfclub head for a long term. Further, it is superior in maintenancecharacteristics, the handling characteristics, and the resource savingcharacteristics.

The golf club head of this invention has the following structure.

A golf club head comprising: a shaft fixing body; a balance adjustingportion that locates at back face side of the shaft fixing body, thebalance adjusting portion holds replaceable weights of a variety ofdensity and mass; a face side connecting portion that is located at faceside of the shaft fixing body and detachably connects to the balanceadjusting portion holding the shaft fixing body therebetween.

According to the golf club head of present invention, the followingadvantageous effects will be provided.

(1) Users can choose and change the shaft fixing body, the balanceadjusting portion and the shape and materials of the face sideconnecting portion. Then the mounting position and the angle of theshaft, a curve, the shape of the whole head, mass and the center ofgravity balance will be changed greatly. Thus the golf club head withsuperior flexibility of the shape selection and versatility will beprovided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective illustration of the face side of the golf clubhead of the embodiment 1.

FIG. 1B is a perspective illustration of back face side of the golf clubheads of the embodiment 1.

FIG. 2 is an exploded perspective view of the golf club head of theembodiment

FIG. 3A is a side view of the shaft fixing body of the golf club head ofthe embodiment 1.

FIG. 3B is a rear view of the shaft fixing body of the golf club head ofthe embodiment 1.

FIG. 4 is a section schematic view of the balancer storing portion ofthe golf club head of the embodiment 1.

FIG. 5 is an exploded perspective view showing the modified example ofthe shaft fixing body in the golf club head of the embodiment 1.

DETAILED DESCRIPTION OF THE INVENTION Embodiment 1

The golf club head of the embodiment 1 of the present invention will beexplained referring the drawings as follows.

FIG. 1A is a perspective illustration of the face side of the golf clubhead of the embodiment 1, and FIG. 1B is a perspective illustration ofthe back face side of the golf club head of the embodiment 1.

In FIG. 1, a symbol 1 shows a golf club head of the embodiment 1. Asymbol 1 a shows a face surface of the golf club head 1. A symbol 1 bshows a back face surface of the golf club head 1. A symbol 1 c showsthe top surface of the golf club head 1. A symbol 2 shows a shaft fixingbody of the golf club head 1 with a hazel 3 shaped thereon, A symbol 4shows a balance adjusting portion that is allocated at the back facesurface 1 b side and is capable of detachably holding weights of avariety of density and mass in balancer storing portions 5 a, 5 b asmentioned later. A symbol 7 shows a face side connecting portion that isallocated at the face surface 1 a of the shaft fixing body 2 and isdetachably connected with the balance adjusting portion 4 as shown inFIG. 1A.

A detail of each part of the golf club head of the embodiment 1 will beexplained as follows.

FIG. 2 is an exploded perspective view of the golf club head of theembodiment 1, FIG. 3A is a side view of the shaft fixing body of thegolf club head of the embodiment 1, FIG. 3B is a rear view of the shaftfixing body of the golf club head of the embodiment 1, FIG. 4 is asection schematic view of the balancer storing portion of the golf clubhead of the embodiment 1.

At first, the shaft fixing body of the golf club head of the embodiment1 will be explained hereinafter.

In FIGS. 2 to 4, a symbol 2 a shows a face side recess (FIG. 2) that isshaped on the face side 1 a of the shaft fixing body 2. A symbol 2 bshows two shaft halls made to the shaft fixing body 2. A symbol 2 cshows a fitting protrusion (FIGS. 3 and 4) that is allocated at the sideof the back face surface 1 b of the shaft fixing body 2 and is shaped ascapable of fitting with an opening 6 of the balancer storing portion 5a, 5 b. A symbol 2 d shows a back face side recess (FIG. 3B) that isshaped as rectangle shape at the center of the back face surface 1 b(FIG. 2) of the of the shaft fixing body 2. A symbol 2 e shows an ICchip storing portion that is shape as a recess at tow side of the backface surface 1 b of the shaft fixing body 2, and an IC chip will beembedded therein.

In this the embodiment 1, the hazel (a shaft fitting portion) 3 isshaped at heel side of the shaft fixing body 2 as had shown in FIGS. 1and 2. The position and the angle of the hazel 3 can be chosenappropriately. When a plurality of the shaft fixing bodies 2 withdifferent positions and angles of the hazels 3 are prepare beforehand,the angle and the direction of the shaft can be changed by justreplacing the shaft fixing body 2. Therefore, many users with differentpreferences and handedness are satisfied with as little stock aspossible. That means the golf club head is superior in mass productivityand easiness of inventory control. In addition, as shown in FIGS. 3 and4, the fitting protrusion 2 c that will be fit with the opening 6 of thebalancer storing portion 5 a, 5 b is allocated at the back face surface1 b of the shaft fixing body 2. Thus the shaft fixing body 2 and thebalance adjusting portion 4 can be temporary positioned very easily. Itwill contribute to effectiveness of replacing work of fixation screw 11.

On the back face side recess 2 d shown in FIGS. 1B and 3B, anappropriate back face plate, not shown, can be fit or glued with asnecessary. As to the materials of the back face side plate, depending onthe usage such as for playing or for displaying, an appropriate materialcan be chosen from various metal such as tungsten, stainless steel,titanium, gold and platinum, or glass, or a synthetic resin. The surfaceof the back face plate can be carved with its user name or decoratedwith various colors or designs. Especially, for private usage ordisplaying usage, the back face plate can be decorated with inparticular it with precious metals or jewels.

An IC chip can be embedded in the IC chip storing portion 2 e in FIG.3B. The IC chip can memorize user personal information (a full name or auser registration number), specification information of the golf clubhead (a serial number, mass, position of the center of gravity, mass orthe length of the shaft), and used for managing them. Variousinformation (data) memorized on the IC chips are read from them bycomputers. They are stored, managed or updated on the computers. Thusthe information about the users and the golf club heads can be surelymanaged without exception. By memorizing the record of buying andselling and the transfer of the golf club head, the history of the userin the IC chips, it will be easily and surely decided whether the golfclub head is an original or an imitation (whether it was put into themarket by authorized dealers or not) or whether the golf club head is astolen goods or not. Thus it contributes in reliability of distributionmanagement.

In addition, the position of the IC chip storing portion 2 e can beanywhere where it can properly communicate with a leader writer. It willbe better where it is not exposed to outer environment and will notreceive any shocks from outer world while it is being used ortransported is chosen as the position for the IC chip storing portion 2.It is preferable to shape the IC chip storing portion 2 according to theouter shape of the IC chips. If the IC chip storing portion 2 e isformed on the back face surface side of the shaft fixing body 2, the ICchip will not be affected by the shock of hitting and since the IC chipis protected by the balance adjusting portion 4, it will preventaccidents such as being destroyed by external force or being lost. Inaddition, the IC chip storing portion 2 e may be allocated on either towside or heel side of the shaft fixing body 2. However, if it isallocated at the heel side, as shown in FIG. 3B, swinging motion of theplayer will be stable and unnecessary turning motion of user's wristwill be avoided. Thus it is superior in orbital stability.

A detail of the balance adjusting portion and face side connectingportion of the golf club head of the embodiment 1 will be explained asfollows.

In FIGS. 2 and 4, symbols 5 a, 5 b show the balancer storing portion(FIG. 2) which are shaped to be open at tow side and heel side of theshaft fixing body 2. A symbol 6 shows an opening (FIG. 2) of thebalancer storing portion 5 a, 5 b. A symbol 8 shows a plate main body ofthe face side connecting portion 7 that will be fit to the face siderecess 2 a of the shaft fixing body 2. Symbols 8 a show twothrough-holes which are made on the plate main body 8 and are adjustedto the position of the shaft halls 2 b of the shaft fixing body 2. Asymbol 8 b shows a fitting recess that is shaped around the through hole8 b at face surface 1 a of the plate main body 8. A symbol 9 shows aninsert shaft that will be inserted into the through-hole 8 a from theplate main body 8 of the shaft fixing body 2. A symbol 9 a shows a headof the insert shaft 9 that will be fit to the fitting recess 8 b of thefitting recess 8 b of the plate main body 8. A symbol 9 b shows aconnecting internal thread that is shaped at tip portion of the insertshaft 9. A symbol 10 shows a cover plate that is put on the surface (theface side) of the plate main body 8 of the face side connecting portion7. A symbol 11 shows a plurality of weights which are shaped as ringshape and held in the balancer storing portion 5 a, 5 b while the insertshaft 9 are inserted into the through-hole 11 a thereof. A symbol 12shows a fixation screw that will be inserted from a fixationthrough-hole 6 b (FIG. 4) and is screwed together with the connectinginternal thread 9 b of the insert shaft 9 of the face side connectingportion 7. A symbol 12 a shows a shaft portion of the fixation screw 12on which an external thread is made in order to be screwed together withthe connecting internal thread 9 b. A symbol 12 b shows a head of thefixation screw 12 that is shaped at the end of the shaft portion 12 eand will be fit to counterbore 6 a that is shaped around the fixationthrough-hole 6 b on the back face surface 1 b side. Each of a symbol 12c shows each tool fitting recesses (FIGS. 4 and 1B) shaped on the head12 b in order to fit a tool. The tool will be used to turn the fixationscrew 12 in order to screw or unscrew the fixation screw 12.

As for the materials of the shaft fixing body 2 and the balanceadjusting portion 4, metals such as magnesium, titanium, the stainlesssteel or the synthetic resins can be used. When an engineering resinsuch as the polycarbonate is used for them, it will be superior inmechanical strength and light weight. Further it will prevent damage bythe external force. In addition, by selecting the materials, the totalmass of the golf club head can be adjusted. As for the materials of theweight 11, metals of heavy specific gravity such as tungsten, brass,iron, copper and gold, or metals of light specific gravity such asmagnesium, aluminum, titanium, or synthetic resin such as ABS resin orPC resin, and synthetic rubber can be used. Density (specific gravityand materials) and the mass of each weight 11 can be chosenappropriately. And it is not necessary that all weights 11 are the same.An appropriate allocation (a combination) of different kind of weights11 will adjust the center of gravity position of the front and backdirection. In addition, the outer shape of the weight 11 is notnecessarily ring shape. The shape of rectangle or polygon or thecombination thereof can be chosen as well.

The shape, the size and the thickness of the plate main body 8 and thecover plate 10 of the face side connecting portion 7 can beappropriately selected. In addition, as for the materials of the platemain body 8 and the cover plate 10, not only various metals such astungsten, stainless steel and titanium, but also the synthetic rubbercan be used. By choosing shape or materials of the plate main body 8 andcover plate 10, the mass and the center of gravity balance of the wholegolf club head 1 can be adjusted. In this the embodiment 1, the platemain body 8 of the face side connecting portion 7 and the insert shaft 9are made of different member. A connecting shaft member can beintegrally shaped to protrude from the back face surface 1 b (the shaftfixing body 2) of the plate main body 8. And internal thread can beshaped in order to be screwed together with the fixation screw 12. Inaddition, in the present embodiment 1, outer thread is shaped on thefixation screw 12 and the connecting internal thread 9 b is shaped onthe insert shaft 9. However, the internal thread may be shaped on thefixation screw 12 and the outer thread may be shaped on the insert shaft9 (or connecting shaft portion).

The shape of the face side recess 2 a is formed in order to fit with theshape of the plate main body 8 and cover plate 10 of the face sideconnecting portion 7. When the depth of the face side recess 2 a isshaped to match with the total thickness of the plate main body 8 andcover plate 10 of the face side connecting portion 7, The surface of theface surface 1 a of the shaft fixing body 2 and the surface of the coverplate 10 will be flat. Thus the ball can be surely hit, and thereliability of the shot will be superior. In addition, in case of theplate main body 8 of the face side connecting portion 7 and the insertshaft 9 are made integrally, the cover plate 10 can be omitted.

The modified embodiment of the shaft fixing body of the golf club headin the embodiment 1 will be explained hereinafter.

FIG. 5 is an exploded perspective view showing the modified example ofthe shaft fixing body in the golf club head of the modified embodiment1.

The modified embodiment and the embodiment 1 differs in that the shaftfixing body 2 a comprises an peripheral frame member 22 with a hollowportion 22 a and a mass adjusting portion 23 that is made as a plateshape and is capable of being detachably stored in the hollow portion ofthe peripheral frame member 22. The total mass and the center of gravityposition of the shaft fixing body 2 a can be adjusted by changingmaterials, mass, or the mounting position of the mass adjusting portion23. For example, stainless steel can be used as a material of peripheralframe member 22 and a combination of aluminum, titanium, and stainlesssteel can be used as material of the mass adjusting portion 23.

In addition, as to the mass adjusting portion 23, it is only required todetachably stored in the hollow portion 22 a of the peripheral framemember 22. When the outer shape of the mass adjusting portion 23 isformed to match with the hollow portion 22 a, the mass adjusting portion23 will be firmly held in the hollow portion 22 a by just an insertingoperation only. Thus it will contribute to effectiveness of replacingwork. In addition, the mass adjusting portion 23 can be shaped as aplate shape as shown in FIG. 5. However it is not necessary to be formedas same thickness with the peripheral frame member 22. Thin massadjusting portion 23 can be slightly moved to the face surface 1 a sideand the back face surface 1 b side, or a plurality of the mass adjustingportion 23 of different materials or the thickness can be combined to beplaced. Thus the total mass and the center of gravity position of thefront and back direction of the shaft fixing body 2 a can be easilyadjusted.

In addition, the thickness and materials of the mass adjusting portion23 is not necessarily to be uniform. For example, the thickness andmaterials of the mass adjusting portion 23 can be changed to bedifferent at each place such as top surface side and the sole side orthe heel side and the tow side. Thus the center of gravity position canbe adjusted as to the top and bottom direction and the right and leftdirection. In addition, when thin board shaped mass adjusting portion 23is used, only peripheral portion can be shaped as thick enough in orderto improve fixation stability against the peripheral frame member 22. Inaddition, in case of latching protrusions are formed along with theinternal surface of the peripheral frame member 22, or a partition wallthat partitions interior of the hollow portion 22 a to the face side andthe back face side therein is formed, the peripheral portion or thesurface of the mass adjusting portion 23 can be abut against thelatching protrusions or the partition wall. Thus it ensures correctpositioning. Furthermore, any apertures can be formed on the partitionwall as necessary in order to adjust the mass and the center of gravity.

By the way the hazel (shaft fixing portion) is formed in order to attachthe shaft. Therefore, if a plurality of the shaft fixing body withdifferent position and an angle of the shaft fixing portion are preparedbeforehand, the angle of the shaft, a direction and bending can beeasily changed by just replacing the shaft fixing body only. It can copewith a variety of user preference and the handedness of many users bylittle stocks. It will be superior in mass productivity and the easinessof the inventory control.

As for the materials of the shaft fixing body and the balance adjustingportion, metals such as magnesium, titanium, the stainless steel or thesynthetic resins can be used. When an engineering resin such as thepolycarbonate is used for them, it will be superior in mechanicalstrength and light weight. Further it will prevent damage by theexternal force. In addition, by selecting the materials, the total massof the golf club head can be adjusted.

The balance adjusting portion should be able to adjust the balance(total mass and the center of gravity position) of the golf club head byputting on and taking off weights of different density and the mass.

The shape, the size and the thickness of the face side connectingportion can be appropriately selected. In addition, as for the materialsof the face side connecting portion, not only various metals such astungsten, stainless steel and titanium, but also the synthetic rubbercan be used. By choosing shape or materials of the face side connectingportion, the mass and the center of gravity balance of the whole golfclub head can be widely adjusted.

The balance adjusting portion and the face side connecting portionshould be detachably connected with each other, and if they areconnected by bolts and nuts, it will be easier in replacing work andsuperior in assembling and disassembling work. Further, since fixationwill be certain and stable, it will be preferable.

Density (specific gravity and materials) and the mass of each weightthat will be held in the balance adjusting portion can be chosenappropriately. And it is not necessary that all weights are the same. Inaddition, the external shape of the weights can be circle, rectangular,the shape of polygon or any combination thereof. If a through-hole forfixation is formed at the central portion, the weights will be easilyand surely fixed to the balance adjusting portion by using a connectingrod that connect the face side connecting portion with the balanceadjusting portion.

As for the materials of the weights, in addition to the metals of heavyspecific gravity such as tungsten, brass, iron, copper and gold, ormetals of light specific gravity such as magnesium, aluminum, titanium,a combination of synthetic resin such as ABS resin or PC resin withsmaller (lighter) specific gravity than those of metals, and syntheticrubber can be used.

In the shaft fixing body, it is preferable to form the IC chip storingportion for embedding the IC chip therein on. The IC chip embedded inthe IC chip storing portion can memorize user personal information (afull name or a user registration number), specification information ofthe golf club head (a serial number, mass, position of the center ofgravity, mass or the length of the shaft) while keeping the relationshiptherebetween. Those information can be easily managed with the shaftfixing body. Various information (data) memorized on the IC chips asnecessary are read from them by computers. They are stored, managed orupdated on the computers. Thus the information about the users and thegolf club heads can be surely managed without exception, thus thecertainty and the reliability of the data management is superior. Bymemorizing the record of buying and selling and the transfer of the golfclub head, the history of the user in the IC chips, it will be easilyand surely decided whether the golf club head is an original or animitation (whether it was put into the market by authorized dealers ornot) or whether the golf club head is a stolen goods or not. Thus itcontributes in reliability of distribution management.

The IC chip should be able to read and write data. Especially thenon-contact IC tag that can be read or written wirelessly, can be usedto data read and write within a certain distance from a reader-writer.It is not necessarily disassembled or contacted with a reader-writer, itcontributes to use characteristics and is preferable. In addition, aposition of the IC chip storing portion should be the position that cancommunicate with a leader writer. It will be better to be chosen whereit is not exposed to outer environment and will not receive any shocksfrom outer world while it is being used or transported is chosen as theposition for the IC chip storing portion. Further, It is preferable toshape the IC chip storing portion according to the outer shape of the ICchips. If the IC chip storing portion is formed on the back face surfaceside of the shaft fixing body, the IC chip will not be affected by theshock of hitting, And since the IC chip is protected by the balanceadjusting portion, it will prevent accidents such as being destroyed byexternal force or being lost. In addition, the IC chip storing portionmay be allocated on either tow side or heel side of the shaft fixingbody. However, if it is allocated at the heel side, swinging motion ofthe player will be stable and unnecessary turning motion of user's wristwill be avoided. Thus it is superior in orbital stability.

The reader-writer and the computer are connected with USB (UniversalSerial Bus) cables, and they can mutually transfer data therebetween.The update of balance adjustment information or the three-dimensionalinformation of the center of gravity position will be performed atdealers where the golf club head was purchased or maintenance shops.Various information memorized in the IC chip can be managed along withuser information (customer information) at each stores. In addition,although there are various applicable model, the golf club head will beparticularly preferable for a golf putter.

According to the above mentioned structures, the golf club head operatesas follows.

(1) Since the golf club head comprises at least three layers such as theshaft fixing body, the balance adjusting portion and the face sideconnecting portion, the mounting position and the angle of the shaft,the shape of the whole head, mass and the center of gravity balance willbe changed in wide range by changing and replacing the shape andmaterials of each parts. Thus it is superior in flexibility of the shapechoice and versatility.

(2) Since the balance adjusting portion that can detachably hold weightsof a variety of density and mass is equipped, when a plurality ofweights with different density (materials), mass and allocation arecombined, the mass and the center of gravity position of the head can beeasily adjusted, and the maintenance characteristic will be superior.

(3) Since the face side connecting portion that is detachably connectedwith the balance adjusting portion while holding the shaft fixing bodytherebetween is equipped, the balance adjusting portion and the faceside connecting portion can surely hold the shaft fixing bodytherebetween, thus it will contribute to fixing stability anddurability. Further, since damaged parts can be easily replacedindividually, it is superior in resource saving characteristics and themaintenance characteristic.

(4) When the materials (mass) of the face side connecting portion ischosen and replaced, the center of gravity position of the front andback direction of the head can be adjusted. Further depending on thehardness of the face surface (the surface) of the face side connectingportion, the touch feeling of the ball can be adjusted, thus itcontributes to the variety of user preference. Therefore it is superiorin work effectiveness of the center of gravity position adjustment anddesign flexibility of the head.

(5) When the center of gravity of the head is moved to the face side orthe sole side by changing shape and materials of each parts, ormaterials and allocation of the weights, a face surface becomes to hitto a certain portion of the ball (position that is lower than a centerof gravity on the equator) that is lower than the core of the ball. Thusit will increase backspin turns, and becomes easier to control the ball.Especially for a short putting or putting on a fast running green, thegolf club head is easier to use.

(6) When the center of gravity of the head is moved to the crown side orthe back face surface side by changing shape and materials of eachparts, or materials and allocation of the weights, a face surfacebecomes to hit to a certain portion of the ball (position that is closeto the center of gravity on the equator) that is close to the core orhigher than the core of the ball. Thus it will reduce loss at impactingmoment, and increases running distance.

(7) When the balance adjusting portion or the face side connectingportion are replaced in order to adjust mass and the center of gravityposition, the shaft fixing body can be kept using and will not benecessary to throw away. Thus it will be superior in resource savingcharacteristics and the environmental protection characteristic.

According to the golf club head of claim 2, the above shaft fixing bodycomprises a peripheral frame member, and a mass adjusting portion thatis detachably allocated in the hollow portion of the above peripheralframe member.

According to the above mentioned structures, the golf club head operatesas follows in addition to the invention of claim 1.

(1) Since the present invention is equipped with the mass adjustingportion that is capable of being detachably stored in the hollow portionof the peripheral frame member, when the materials, mass, a mountingposition of the mass adjusting portion are changed as necessary, acenter of gravity position of the shaft fixing body can be widelyadjusted. Therefore it contributes to user preference, and it issuperior in versatility and design flexibility.

The materials of the peripheral frame member and the mass adjustingportion can be chosen appropriately as they will be formed integrallywith the shaft fixing body. They are not necessarily differentmaterials, and may use the same materials. For example, stainless steelmay be used as material of the peripheral frame member and combinationof aluminum, titanium, stainless steel may be used as material of themass adjusting portion.

The mass adjusting portion should be able to be detachably stored in thehollow portion of the peripheral frame member. When the outer shape ofthe mass adjusting portion is formed to match with the hollow portion,it will be easy to firmly fit the mass adjusting portion to the hollowportion. Thus it will contribute to effectiveness of replacing work.

In addition, although the mass adjusting portion can be shaped as aplate shape, it is not necessary to be formed as same thickness andwidth with the hollow portion of the peripheral frame member. Thin massadjusting portion can be slightly moved to the face surface side or theback face surface side, or a plurality of the mass adjusting portion ofdifferent materials or the thickness can be combined to be placed. Thusthe total mass and the center of gravity position of the front and backdirection of the shaft fixing body can be easily adjusted.

In addition, the thickness and materials of the mass adjusting portionis not necessarily to be uniform. For example, the thickness andmaterials of the mass adjusting portion can be changed to be differentat each places such as top surface side and the sole side or the heelside and the tow side. Thus the center of gravity position can beadjusted as to the top and bottom direction and the right and leftdirection.

In addition, when thin board shaped mass adjusting portion is used, onlyperipheral portion can be shaped as thick enough in order to improvefixation stability against the peripheral frame member. In addition, incase of latching protrusions are formed along with the internal surfaceof the peripheral frame member, or a partition wall that partitionsinterior of the hollow portion to the face side and the back face sidetherein is formed, the peripheral portion or the surface of the massadjusting portion can be abut against the latching protrusions or thepartition wall. Thus it ensures correct positioning.

According to the golf club head of claim 3, the balance adjustingportion comprises balancer storing portions that open toward the shaftfixing body side and allocated at tow side portion and/or heel sideportion, fixation through-holes made to be open on the back face side ofeach of the balancer storing portions, and fixation screws that areinserted from the fixation through-holes and are connected to the faceside connecting portion.

According to the above mentioned structures, the golf club head operatesas follows in addition to the invention of claim 2.

(1) Since the balance adjusting portion is equipped with the balancerstoring portions which open toward the shaft fixing body side andallocated at tow side portion and/or heel side portion, the center ofgravity position of the right and left direction and the front and backdirection of the head can be adjusted in a wide range depending onuser's habit or preference by selecting a number of the weights,materials of each weights (mass), and combination of their allocation.

(2) Since the balancer storing portion of the balance adjusting portionhas openings toward the shaft fixing body side, the openings of thebalancer storing portion can be covered by the shaft fixing body, it isnot necessary to prepare other members such as lids separately, thus itreduces a number of parts. Further, it protects the weights in itselffrom wind, rain and external forces, thus it contributes to preventdamage or loss, and can be superior to the durability and the handlingcharacteristics.

(3) Since the balance adjusting portion is equipped with the fixationthrough-holes made to be open on the back face side of each of thebalancer storing portions, and the fixation screws that are insertedfrom the fixation through-holes and are connected to the face sideconnecting portion, the balance adjusting portion and the face sideconnecting portion can be easily and surely connected together, thus itcontributes to the easiness of assembling and disassembling, and it willbe superior to maintenance characteristics.

(4) Since the balance adjusting portion is equipped with the fixationthe fixation screws that are inserted from the fixation through-holesand are connected to the face side connecting portion, it is notnecessary to form an external thread and an internal thread to thebalance adjusting portion, and thus is superior in workability. When thefixation screws become worn, deformed or damaged, no other parts thanthe fixation screws need to be replaced, thus the balance adjustingportion can be used for a long term and the golf club head is superiorto resource saving characteristics and environmental protectioncharacteristics.

Since the balancer storing portion of the balance adjusting portion hasopenings toward the shaft fixing body side, in case the fittingprotrusion that fit with the opening of the balancer storing portion isformed on the shaft fixing portion, the shaft fixing body and thebalance adjusting portion can be temporary positioned very easily, thusit will contribute to effectiveness of replacing work of fixation screw.The fixation screw should be able to be screwed together with the backface side connecting portion, and the fixation screw can be an internalthread or an outer thread.

In addition, the internal screw or the outer screws which will bescrewed together with the fixation screw may be directly formed on theface side connecting portion. Further, there may be only a through-holeon the face side connecting portion, and the insert shaft that isequipped with the internal screw or the outer screws may be attached byforcible insertion.

According to the golf club head of claim 4, the face side connectingportion comprises a plate main body, and a connecting shaft member thatis shaped to protrude from the shaft fixing body side of the plate mainbody and is capable of being screwed together with the fixation screw.

According to the above mentioned structures, the golf club head operatesas follows in addition to the invention of claim 3.

(1) Since the face side connecting portion is equipped with the platemain body, and the connecting shaft member that is shaped to protrudefrom the shaft fixing body side of the plate main body and is capable ofbeing screwed together with the fixation screw, when the fixation screwand the connecting shaft member are screwed together with each other,the balance adjusting portion and the face side connecting portion canbe easily connected, thus they will be firmly fixed. It contributes tothe work effectiveness of assembling and disassembling, and it will besuperior in fixing stability and fixing certainty.

Either one of the fixation screw and the connecting shaft member may beformed with the outer thread, and the another should be formed with theinner thread.

When the weights are magnetized, a plurality of the weights can behandled as one unit, thus it is superior in not only easiness ofreplacing work nor the easiness of the adjusting work for the center ofgravity position, but also in suppressing delicate vibration. Thereforeit is superior in usability. In addition, it is not necessary tomagnetize all of the weights, but some of them may be magnetized. Thenthe rest of the unmagnetized weights and the magnetized weights may beused in combination.

According to the golf club head of claim 5, the weight is detachablyinserted by a shaft portion of the fixation screw or the connectingshaft member.

According to the above mentioned structures, the golf club head operatesas follows in addition to the invention of claim 4.

(1) Since each of the weights are detachably inserted by the shaftportion of the fixation screw or the connecting shaft member, aplurality of weights can be surely held in the balancer storing portion,the center of gravity does not move, and it is superior in the handlingcharacteristic.

The length of the shaft portion of the fixation screw and the connectingshaft member can be appropriately adjusted. According to the balance ofthe lengths, the weights may be inserted with the shaft portion of thefixation screw or the shaft connecting member and held by them.

According to the golf club head of claim 6, the face side connectingportion comprises a plate main body, a through-hole made to be open onthe plate main body, and an insert shaft that is inserted into thethrough-hole and screwed together with the fixation screw.

According to the above mentioned structures, the golf club head operatesas follows in addition to the invention of claim 3.

(1) Since the face side connecting portion comprises the plate mainbody, the through-hole made to be open on the plate main body, and theinsert shaft that is inserted into the through-hole and screwed togetherwith the fixation screw, when the fixation screw and the insert shaftare screwed together with each other, the balance adjusting portion andthe face side connecting portion can be easily connected, thus they willbe firmly fixed. It contributes to the work effectiveness of assemblingand disassembling, and it will be superior in fixing stability andfixing certainty.

(2) Since the internal thread or the outer thread are made with theinsert shaft that is forcibly inserted into the through-hole of theplate main body, It is not necessary to directly form the internalthread or the external thread to the plate main body, thus it issuperior in workability. When the insert shaft become worn, deformed ordamaged, no other parts than the insert shaft need to be replaced, thusthe plate main body can be used for a long term and the golf club headis superior to resource saving characteristics and environmentalprotection characteristics.

According to the golf club head of claim 7, the face side connectingportion comprises a fitting recess that is formed on the face surfaceside of the plate main body and is fit to the head of the insert shaft.

According to the above mentioned structures, the golf club head operatesas follows in addition to the invention of claim 6.

(1) Since the face side connecting portion is equipped with the fittingrecess that is formed on the face surface side of the plate main bodyand is fit to the head of the insert shaft, when the fixation screw isbeing screwed together with the insert shaft member, they will preventcorotation. Thus the fixation screw and the insert shaft will be easilyand surely screwed together. And it contributes to the workeffectiveness of assembling and disassembling, and is superior in fixingcertainty.

(2) Since the head of the insert shaft is fit with the fitting recess ofthe plate main body, the head of the insert shaft will not abut from theface surface side of the plate main body. It prevents from contact ofthe head of insert shaft and the ball, thus the ball will be surely hitwith the surface of the plate main body. Therefore it is superior inusability.

The shape of the head of the insert shaft may preferably be in form ofpolygon or oval shape. Since even if there is a gap between the fittingrecess and the head of insert shaft, it will surely prevent corotationof the fixation screw and the insert shaft member when they are screwedtogether.

In addition, it will prevent from abutting the head of the insert shaftmember from the fitting recess by setting the depth of the fittingrecess be equal or greater with the height of the head of the insertshaft member.

In addition, the surface (a face side) of the plate main body of theface side connecting portion may be covered by the cover plate. Itprevents a step made between the head of the insert shaft member and thesurface of the plate main body, and it contributes to the stability ofthe ball running line. Further, the mass of the golf club head may befine-tuned by materials or the thickness of the cover plate, itcontributes to design flexibility and versatility.

According to the golf club head of claim 8, the weight is detachablyinserted by a shaft portion of the fixation screw or the connectingshaft member.

According to the above mentioned structures, the golf club head operatesas follows in addition to the invention of claims 6 and 7.

(1) Since each of the weights are detachably inserted by the shaftportion of the fixation screw or the insert shaft member, a plurality ofweights can be surely held in the balancer storing portion, the centerof gravity does not move, and it is superior in the handlingcharacteristic. The length of the shaft portion of the fixation screwand the insert shaft member can be appropriately adjusted.

According to the balance of the lengths, the weights may be insertedwith the shaft portion of the fixation screw or the insert shaft memberand held by them.

According to the golf club head of claim 9, a face side recess that isallocated at face surface side of the shaft fixing body and the platemain body of the face side connecting portion is fit thereto.

According to the above mentioned structures, the golf club head operatesas follows in addition to the invention of claims 4 to 8.

(1) Since the golf club head is equipped with the face side recess thatis fit with the plate main body of the face side connecting portionformed at face surface side of the shaft fixing body and, when thefixation screw and the face side connecting portion are fixed together,the shaft fixing body and the face side connecting portion can betemporary positioned very easily, thus it contributes to ease thereplacing work of the fixation screw, and to the work effectiveness ofassembling and disassembling. The shape of the face side recess isformed according to the shape of the face both sides connecting portion.

When the depth of the face side recess is set to be equal with thethickness of the face side connecting portion, the surface of the faceside connecting portion will be flat with the face side of the shaftfixing body. The ball can be surely hit, and it contributes to thereliability of shot.

According to the invention of claim 2, in addition to the merits ofclaim 1, following merits will be presented.

(1) The mass and the center of gravity position of the shaft fixing bodycan be widely changed by selecting the materials, mass and the mountingposition of the mass adjusting portion, the golf club head which can beadjusted user preference and is superior in the versatility and designflexibility will be provided.

According to the invention of claim 3, in addition to the merits ofclaim 2, following merits will be presented.

(1) Since the shaft fixing body can be easily and surely sandwiched bythe balance adjusting portion and the face side connecting portion, thegolf club head which was superior in the maintenance characteristic willbe provided.

According to the invention of claim 4, in addition to the merits ofclaim 3, following merits will be presented.

(1) When the fixation screw that is inserted from the back face side ofthe balancer storing portion and the connecting shaft member of the faceside connecting portion are screwed together with each other, thebalance adjusting portion and the face side connecting portion can beeasily connected, thus they will be firmly fixed. The golf club headthat contributes to the work effectiveness of assembling anddisassembling, and is superior in fixing stability and fixing certaintywill be provided.

According to the invention of claim 5, in addition to the merits ofclaim 4, following merits will be presented.

(1) Since a plurality of weights are detachably inserted by the shaftportion of the fixation screw or the connecting shaft member, theweights are surely held in the balancer storing portion, the center ofgravity does not move. The golf club that is superior in the handlingcharacteristic will be provided.

According to the invention of claim 6, in addition to the merits ofclaim 3, following merits will be presented.

(1) When the fixation screw that is inserted from the back face side ofthe balancer storing portion and the insert shaft member of the faceside connecting portion are screwed together with each other, thebalance adjusting portion and the face side connecting portion can beeasily connected, thus they will be firmly fixed. The golf club headthat is superior in work effectiveness of assembling and disassembling,and in fixing stability and fixing certainty will be provided.

According to the invention of claim 7, in addition to the merits ofclaim 6, following merits will be presented.

(1) Since the head of the insert shaft is fit with the fitting recessthat is formed on the face surface side of the plate main body, when thefixation screw is being screwed together with the insert shaft member,they will prevent corotation. Thus the fixation screw and the insertshaft will be easily and surely screwed together. Thus the golf clubhead that contributes to the work effectiveness of assembling anddisassembling, and is superior in fixing certainty will be provided.

According to the invention of claim 8, in addition to the merits ofclaims 6 and 7, following merits will be presented.

(1) Since each of the weights are detachably inserted by the shaftportion of the fixation screw or the insert shaft member, a plurality ofweights can be surely held in the balancer storing portion. Thus thegolf club head whose center of gravity does not move, and is superior inthe handling characteristic will be provided.

According to the invention of claim 9, in addition to the merits ofclaims 4 to 8, following merits will be presented.

(1) Since the plate main body of the face side connecting portion is fitwith the face side recess formed at face surface side of the shaftfixing body, when the fixation screw and the face side connectingportion are fixed together, the shaft fixing body and the face sideconnecting portion can be temporary positioned very easily. Thus itcontributes to ease the replacing work of the fixation screw. And thegolf club head that is superior in the work effectiveness of assemblingand disassembling will be provided.

While the invention has been particularly shown and described withrespect to preferred the embodiment is thereof, it should be understoodby those skilled in the art that the foregoing and other changes in formand detail may be made therein without departing from the spirit andscope of the invention as defined in the appended claims.

While the invention has been particularly shown and described withrespect to preferred the embodiment is thereof, it should be understoodby those skilled in the art that the foregoing and other changes in formand detail may be made therein without departing from the spirit andscope of the invention as defined in the appended claims.

1. A golf club head comprising: a shaft fixing body; a balance adjustingportion that locates at back face side of the shaft fixing body, thebalance adjusting portion holds replaceable weights of a variety ofdensity and mass; a face side connecting portion that is located at faceside of the shaft fixing body and detachably connects to the balanceadjusting portion holding the shaft fixing body therebetween.
 2. Thegolf club head according to claim 1, wherein the above shaft fixing bodycomprises a peripheral frame member, and a mass adjusting portion thatis detachably allocated in the hollow portion of the above peripheralframe member.
 3. The golf club head according to claim 1, wherein thebalance adjusting portion comprises balancer storing portions that opentoward the shaft fixing body side and allocated at tow side portionand/or heel side portion, fixation through-holes made to be open on theback face side of each of the balancer storing portions, and fixationscrews that are inserted from the fixation through-holes and areconnected to the face side connecting portion.
 4. The golf club headaccording to claim 3, wherein the face side connecting portion comprisesa plate main body, and a connecting shaft member that is shaped toprotrude from the shaft fixing body side of the plate main body and iscapable of being screwed together with the fixation screw.
 5. The golfclub head according to claim 4, wherein the weight is detachablyinserted by a shaft portion of the fixation screw or the connectingshaft member.
 6. The golf club head according to claim 3, wherein theface side connecting portion comprises a plate main body, a through-holemade to be open on the plate main body, and an insert shaft that isinserted into the through-hole and screwed together with the fixationscrew.
 7. The golf club head according to claim 6, wherein the face sideconnecting portion comprises a fitting recess that is formed on the facesurface side of the plate main body and is fit to the head of the insertshaft.
 8. The golf club head according to claim 6, wherein the weight isdetachably inserted by a shaft portion of the fixation screw or theconnecting shaft member.
 9. The golf club head according to claim 4,further comprises a face side recess that is allocated at face surfaceside of the shaft fixing body and the plate main body of the face sideconnecting portion is fit thereto.